Fire Extinguisher Colours: UK Types and Uses Explained

Walk round most sites and you'll find a fire point with two red extinguishers that look almost the same. One has a black band, one has a cream band. In a real fire, with smoke in the cabin and adrenaline running, that small band is the difference between knocking down a burning distribution board and putting water-based foam onto live kit. That's why fire extinguisher colours matter, and why everyone on site should know them.

In the UK, fire extinguisher colours follow BS EN 3 and BS 5306-10. Each has a red body, and a coloured band or panel shows the contents. Red (plain) is water. White is water mist. Cream is foam. Blue is dry powder. Black is carbon dioxide (CO2). Yellow is wet chemical. Specialist Class D powder for metal fires uses a violet panel and is labelled for metal fires only. Always read the label as well as the colour, because the label shows exactly which classes of fire the extinguisher is rated for.

Fire extinguisher colours at a glance

Before 1997, UK extinguishers were painted all over in their identifying colour, so a CO2 extinguisher was entirely black and a powder one entirely blue. The move to BS EN 3 changed that. Now the body is red and a smaller colour zone identifies the contents. If you still find an old fully coloured one, ask your service engineer to look at it.

• Red (water): Class A solids. Not for flammable liquids, cooking oil or live electrical equipment.
• White (water mist): Mainly Class A. Some models are rated for other classes too. Check the label.
• Cream (foam): Class A solids and Class B flammable liquids.
• Blue (dry powder): Classes A, B and C, and electrical equipment. Specialist Class D powders use violet.
• Black (CO2): Class B flammable liquids and electrical equipment.
• Yellow (wet chemical): Class F cooking oils and fats, and usually Class A.

If the letters don't mean much yet, our guide to the classes of fire explains each one with site examples.

Types of fire extinguisher and what each colour means

Water extinguishers (red)

A plain red water extinguisher is the most common type in offices and many site cabins. Water cools burning solids and works well on Class A fires: timber, paper, cardboard, textiles and many plastics.

It must not be used on flammable liquids, because it spreads them, or on cooking oil, where it can cause a violent flare-up. Standard water extinguishers aren't for use on live electrical equipment either. Some are dielectrically tested, which is marked on the label, but that reduces the danger if one is used by mistake near electrics. It isn't a reason to choose water for an electrical fire.

Where you'd see it: offices, stairwells, welfare cabins, stores with paper and packaging, and fire points next to timber stacks and skips.

Water mist extinguishers (white)

Water mist extinguishers break the water into very fine droplets. They have a red body with a white panel. They're mainly used on Class A fires, and some models carry ratings for other classes as well.

Because the ratings vary from one model to another, this is the extinguisher where reading the label matters most. Don't assume a water mist unit covers a particular class unless it says so on the label.

Where you'd see it: offices, hotels, schools and other managed buildings.

Foam extinguishers (cream)

A cream band or panel means foam. Foam works on Class A solids and on Class B flammable liquids, where it forms a blanket over the surface of the liquid to cut off the oxygen and stop vapour escaping.

Foam isn't for cooking oil fires. Like water, it shouldn't be used on live electrical equipment unless the label says it's been dielectrically tested, and even then isolating the power first is the safer route.

Where you'd see it: near paint and solvent stores, fuel stores and refuelling points, workshops, and on sites where Class A and B risks sit side by side.

Dry powder extinguishers (blue)

A blue band means dry powder. Standard ABC powder is rated for Class A, B and C fires and can be used on electrical equipment. That makes it common outdoors on construction sites, on vehicles and plant, and near LPG and fuel stores.

Powder has drawbacks indoors. It forms a dense cloud that reduces visibility and can be hard to breathe in, particularly in small rooms, and it leaves a mess that can damage electronics. For those reasons it's often avoided in offices and enclosed spaces, but that's a decision for your fire risk assessment.

With Class C gas fires, the priority is to isolate the gas supply if that can be done safely. Putting out the flame while gas is still escaping can leave an explosive build-up.

Where you'd see it: outdoor fire points, plant and vehicles, LPG storage cages, fuel bowsers, and garage or workshop areas.

Specialist Class D powder (violet)

Metal fires need a specialist powder extinguisher designed for the metal involved. These now carry a violet panel and are labelled for Class D only and are often fitted with a low-velocity applicator so the powder can be laid gently over the burning metal.

You'll only need one where there's a genuine combustible metal risk, such as magnesium or aluminium swarf in a fabrication area, and the training needs to match.

CO2 extinguishers (black)

A black band means carbon dioxide. CO2 works by displacing oxygen and leaves no residue, which makes it the usual choice for electrical equipment: distribution boards, server rooms, switchgear, office equipment and plant rooms. HSE's construction guidance lists CO2 for electrical fires. It's also rated for Class B flammable liquids.

CO2 isn't rated for Class A fires, because it doesn't cool burning solids enough to stop them re-igniting. There are two other points to know. In a small, poorly ventilated room, discharged CO2 lowers the oxygen level, which is a danger to the user. And the discharge horn gets extremely cold, so it should only be held by the handle or insulated grip.

Where you'd see it: next to electrical distribution boards, generator and plant areas, comms rooms, site offices with lots of IT, and alongside a water or foam unit at most indoor fire points.

Wet chemical extinguishers (yellow)

A yellow band means wet chemical. It's designed for Class F fires in cooking oils and fats. It cools the oil and reacts with it to form a soapy layer on the surface, which helps stop re-ignition. Most wet chemical extinguishers are also rated for Class A.

Where you'd see it: site canteens, welfare cabins with fryers or cookers, staff kitchens and restaurants, and catering units at events. A fire blanket is often fitted as well for small pan fires, for trained people to use.

What about lithium-ion battery extinguishers?

You'll see extinguishers marketed for lithium-ion battery fires, from cordless tools, e-bikes and e-scooters. There's no single BS EN 3 colour or fire class for them, and product claims vary. For most sites, the controls that matter most are about charging: use the manufacturer's charger, avoid unattended overnight charging in cabins and remove damaged batteries. If a battery is on fire, evacuate and call 999, and take advice from your fire risk assessor or local fire and rescue service before buying specialist equipment.

Which extinguisher for which fire?

Most real sites need more than one type. Match extinguishers to the fuels in each area, not to a standard list. Some typical set-ups:

• Site welfare cabin with heater, chargers and microwave: CO2 for electrical, plus water or foam for Class A contents. Wet chemical if there's a fryer.
• Site fuel store and generator: foam or powder for Class B, and CO2 near the generator's electrics.
• Torch-on roofing or other hot works: an extinguisher suited to the materials at the work area, usually water or foam for Class A, plus powder where gas cylinders are in use.
• LPG storage cage: dry powder, sited outside the cage, with the priority on isolation.
• Office, reception or security gatehouse: water or foam, plus CO2 for IT and electrics.
• Plant room or switchroom: CO2.
• Staff kitchen or event catering unit: wet chemical, plus a fire blanket.

On hot works specifically, the extinguisher should be at the work area before the first spark, not at a fire point at the far end of the floor. HSE's guidance on process fire risks lists suitable extinguishers, clearing combustibles and keeping a careful watch throughout the work. Our RAMS for hot works guide covers the rest, and our permit to work page explains how permits back it up.

Only use an extinguisher if you're trained and it's safe

An extinguisher is for a small fire, used by someone trained, with a clear escape route behind them. The first job is always to raise the alarm. If the fire is growing, you don't know what's burning, the room is filling with smoke or your way out could be cut off, leave, close doors behind you if you can, and call 999.

Under the Fire Safety Order, the responsible person must nominate competent people to carry out fire-fighting measures and make sure their number, training and equipment are adequate. A short toolbox talk is a good refresher on which extinguisher sits where, and the fire points belong in every site induction.

Siting, signs and servicing

Colour coding only helps if the right extinguisher is in the right place and works. A few practical points:

• Siting: put extinguishers at identified fire points on escape routes, near exits and close to specific hazards. BS 5306-8 gives detailed guidance on selection and siting, including a commonly quoted maximum travel distance of 30 metres to a Class A extinguisher.
• Signs: the Fire Safety Order requires non-automatic fire-fighting equipment to be easy to get to, simple to use and shown by signs. Many sites add an ID sign at each fire point that shows which extinguisher is for which fire.
• Checks: under BS 5306-3, extinguishers should have a regular visual check by the responsible person (commonly monthly) and a basic service by a competent person every year.
• Extended servicing: BS 5306-3 also sets longer-term servicing, such as discharge testing for water, foam and powder units at five years and an overhaul for CO2 at ten years. Your service provider will tell you what's due.
• Security patrols: check fire points on your route are intact, pins and tamper seals are in place, and nothing blocks them. Report anything missing. Our RAMS for mobile patrol teams covers how to write that into patrol duties.

What the law requires

In England and Wales, the Regulatory Reform (Fire Safety) Order 2005 puts the duties on the responsible person, usually the employer or whoever controls the premises. The gov.uk guidance says the responsible person must carry out a fire risk assessment and review it regularly, put in place and maintain appropriate fire safety measures, plan for an emergency, and give staff information, instruction and training. It also says the types of fire-fighting equipment you need depend on your premises, and that equipment must be properly installed, tested and maintained, with staff trained to use it if necessary.

Article 13 of the Order covers fire-fighting equipment. It says what's appropriate depends on the size and use of the premises, the equipment in it, the physical and chemical properties of the substances likely to be there, and the number of people who could be present. Article 17 requires equipment to be kept under a suitable system of maintenance and in efficient working order.

Construction sites have extra duties under the CDM Regulations 2015. Regulation 32 requires suitable and sufficient fire-fighting equipment, examined and tested at suitable intervals, easy to get to and shown by signs, with workers instructed in its correct use so far as is reasonably practicable. The general duties in the Health and Safety at Work etc. Act 1974 still apply.

In Scotland, fire safety comes under the Fire (Scotland) Act 2005 and the Fire Safety (Scotland) Regulations 2006. In Northern Ireland, it's the Fire and Rescue Services (Northern Ireland) Order 2006 and the Fire Safety Regulations (Northern Ireland) 2010.

All of this starts with the fire risk assessment, which should match extinguishers to the fuels in each area. Our construction fire risk assessment guide shows how to do that on a live site, and our facilities management page covers the same work in occupied buildings.

How swiftRMS helps

swiftRMS is an AI tool that drafts RAMS for construction, security and FM teams. Describe a task, such as cutting steel with a disc cutter in a plant room, and it drafts a risk assessment and method statement with likely fire hazards, suggested controls such as the extinguisher types to have at the work area, and references to the relevant legislation.

It's a draft, not a finished document. A competent person must review, edit and approve it before use, because they know which extinguishers are actually on site, where the fire points are and who's trained. See what the output looks like on our RAMS examples page.

To see a draft for one of your own tasks, try a free RAMS preview with no signup. If it saves you time, there's a 14-day free trial, with no card needed.

Frequently Asked Questions

What are the fire extinguisher colours in the UK?

All UK extinguishers made to BS EN 3 have a red body with a colour zone that shows the contents: plain red for water, white for water mist, cream for foam, blue for dry powder, black for CO2 and yellow for wet chemical. Specialist Class D powders use violet and are labelled for metal fires.

Which fire extinguisher is used for electrical fires?

CO2 (black band) is the usual choice for live electrical equipment, and HSE's construction guidance lists it for electrical fires. Standard dry powder is also rated for electrical equipment but makes a mess and reduces visibility indoors. Where it's safe, isolate the power first.

Can you use a water extinguisher on an electrical fire?

A standard water extinguisher shouldn't be used on live electrical equipment. Some water-based extinguishers are dielectrically tested and marked as such, which reduces the danger if used by mistake, but they aren't the first choice for an electrical fire.

Which extinguisher do I need for a site welfare cabin?

It depends on your fire risk assessment, but a typical cabin has Class A contents and electrical equipment, so a water or foam extinguisher plus a CO2 extinguisher is a common set-up. If there's a fryer or deep pan cooking, add a wet chemical extinguisher and a fire blanket.

How often should fire extinguishers be serviced?

BS 5306-3 sets out a basic service by a competent person every year, regular visual checks in between (commonly monthly), and extended servicing at longer intervals, such as five years for water, foam and powder and ten years for CO2. Keep a record of checks and services.

Why did UK fire extinguisher colours change?

Before 1997, extinguishers were painted all over in their identifying colour. The move to BS EN 3 brought in the red body with a smaller colour zone that shows the contents.

Official Resources

• Workplace fire safety: your responsibilities (gov.uk)
• Fire safety equipment, drills and training (gov.uk)
• Regulatory Reform (Fire Safety) Order 2005, article 13 (legislation.gov.uk)
• General fire safety in construction (HSE)
• HSG168 Fire safety in construction (HSE)
• CDM Regulations 2015, regulation 32 (legislation.gov.uk)